Protecting Arctic marine pipelines against subgouge deformation

Madeline Chua, Professor Andrew Palmer, and Hendrik Tjiawi

Gouging ice masses are a threat to underwater pipelines in the Arctic. The problem is made more severe by the fact that the soil under an ice mass is dragged forward as it gouges, so that a pipeline might not be safe even if it is trenched deep enough for the ice itself to clear it. Subgouge deformation is incompletely understood, and predictions are uncertain.

The scheme describe here makes it possible to eliminate subgouge deformation, by placing a weak layer above the pipeline and below the gouging ice mass. The layer is not strong enough to transmit downwards the shear forces that induce the deformation. The authors describe an improved version that lends itself to straightforward installation.